Luminous article



WITNESSES R. G. FORDYCE.

Lummous ARTICLE.

APPLICATION FILED FEB. 9, 1918.

Patented Aug. 30, 1921.

,8 j INVEI'VTOR UNITED STATES PATENT omce.

RUFUS G. FOBDYGE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR '10 RADIUM DIAL COMPANY, 01 PITTSBURQH, PENNSYLVANIA.

mmmous ARTICLE.

Specification of Letters Patent.

Patented Aug. 30, 1921.

Application filed February 9, 1918. Serial No. 216,214.

To all whom it may concern:

Be it known that I, RurUs'G. Fonoron, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Luminous Articles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in luminous articles and more particularly to those having characters which may be read in the dark,--such, for example, as dials for clocks, watches and other instruments.

One object of my present invention is to provide a dial or similar device of transparent material having pockets or recesses in its rear face containing material which is permanently luminous in the dark,--said pockets or recesses being so formed as to provide unbroken receptacles to confine the luminous material.

A further object is to so construct a dial of transparent material that pockets or recesses shall be formed in its rear face to contain luminous material,said pockets or recesses being of such shape as to form indicating characters for the dial, the closed front portions of said pockets or recesses being formed by the transparent material of the dial.

With these and other objects in view, the invention consists in certain novel features of construction as hereinafter set forth and pointed out in the claim.

In the accompanying drawings, Figure 1 is a view of a watch embodying my improvements. Fig. 2 is an enlarged fragmentary sectional view, and Figs. 3 and 4 are similar sectional views showing slight modifications.

1 represents a watch and 2 indicates my improved luminous disk or dial thereon.

The dial 2 may be made of transparent material, such as celluloid and it may be printed upon, either on its front or its rear ace, in any suitable color or colors, but the printing or coloring of the dial is such that those portions where the indicating characters 1 are to appear shall be left blank and transparent. The material of the disk is recessed in its rear face as at 3 where the said blank transparent portions are left,- said recesses forming pockets, each preferably being made of a shape conforming to that of an indicating character or numeral. The pockets or recesses 3 contain luminous material 4 such as will be permanently luminous in the dark. The said luminous material may comprise radio-sensitive material, such as zinc or calcium sulfid and a small quantity of radio-active material, such as a salt of radium,the latter rendering the radio-sensitive material permanently luminous in the dark. The luminous material may be in the form of a dry powder or it may be intermixed with a suitable adhesive binder and it may be held in place in the pockets and particles prevented from reaching the works of the watch, by a backing 5 applied to the back of the dial. This backing may consist of lacquer or shellac or a metal plate, and this backing may cover the entire back of the dial or only the pocketed portions thereof, as may be desired.

It will be apparent that with the construction of dial hereinbefore described the luminous material which illuminates the figure or character features of the dial will be protected by the unbroken walls of the pockets, and that the transparent fronts of such figures or character features will completely cover the luminous material. The transparent figure or character portions of the dial may be flush with the front face of the latter, or they may be raised or embossed when the pockets are formed, as shown at 6, Fig. 3.

In the form of the invention shown in Fig. 4 I employ a backing plate 7 of metal or other suitable material. To this plate,a disk 8 is cemented or otherwise secured, said disk having perforations 9 forming characters, which perforations are filled with the luminous material 10, and a disk 11 of transparent material is cemented or otherwise secured to the perforated disk. The transparent disk 11, may be provided with suitable printing or coloring on either its front or rear face, in such manner that those portions corresponding to the perforations of the disk 8 shall be left blank and transparent.

Having fully described my invention what I claim as new and desire to secure by Letterslntent, is:

A dial comprising a thin disk of trans- 5 pzuent celluloid having depressions forming characters closed at the front of the dial by material of which the dial is composed, said dial provided with a material rendering it opaque except where the char- 10 acter depressions occur, and luminous material in said character depressions and protected by the transparent portions of the dial forming the characters.

In testimony whereof, I have signed this specification in the presence of two subscribmg witnesses.

' RUFUS G. FORDYGE. Witnesses:

F. H. ALLISON, J osEPH A. KELLY. 

